Process of making a detergent



June 29, 1937.

A. C. BROWN PROCESS OF MAKING A DETERGENT Filed Feb. 11, 1955 INVENTOR. BY 6W WM ATTORNEYS Patented June 29, 1937 UNITED STATES PATENT OFFICE PROCESS OF MAKING A DETERGENT Application February 11, 1935, Serial No. 6,006

7 Claims.

This invention relates to a new detergent composition suitable for many purposes but particularly for laundry washing and for treating textiles in the course of their manufacture. The

detergents which have been most commonly used in the past are the fatty acid soaps. These materials are usually the sodium, potassium or ammonium salts of the higher fatty acids, such as lauric, oleic, palmitic and stearic acids. The

10 most commonly used soaps are the sodium salts of mixed oleic, palmitic and stearic acids. Since these last specified materials are more commonly used at present, the disclosure of this invention is made in relation to these materials,

16 though a wider range, as indicated, may be used to meet special technical problems.

One of the more important uses of soap is the washing of textiles which will be used herein as exemplary. In plant operations as well as in 20 home use of detergents, it is the problem to effect rapidly a solution of the detergent in the water of the wash bath. Soap in bulk or cake form cannot be used advantageously due to the length of time required to form the desired solution.

Soap chips dissolve more rapidly than cake soap, but solutions can be obtained most rapidly and advantageously by the use of powdered soap.

The latter may be manufactured either by grinding soap cake or by liquefying it and spraying 9 it into a heated atmosphere.

When a soap is obtained by saponifying neutral fat by boiling with caustic alkali or by the neutralization of fatty acids with caustic alkalies or alkali carbonates (the two methods commercially 35 employed), the resulting soap contains from 25 to water. Soap in this condition is sufficiently fluid to pour into forms while hot, but becomes solid on cooling. Powdered soap must be substantially dry and whether it be manu- 40 factured by a grinding process, which is relatively expensive, or a spraying process, it is necessary to remove a substantial quantity of water from it. Removal of the water is a tedious process and also is very expensive.

Soaps are very frequently used in conjunction with various mild alkaline salts, such as sodium silicates, sodium carbonate and bicarbonate or sodium phosphate. The use of suitable proportions of soap and alkaline salts has been found, 50 for many purposes, to be not only more economical, but also to give better results than soap alone.

The alkaline salts and soap may be added separately to the detergent bath, or the two may 55 be combined in the soap during the course of its manufacture. Soaps of this type in the past have been termed built soaps. The methods heretofore used for the preparation of powdered built soaps involve at some stage of the manufacturing operation the evaporation of considerable quantities of water from a material which cannot be readily dried. They have also involved very extensive plant equipment, a long manufacturing process, and large quantities of material in the process of being manufactured at a given time.

One object of this invention is to provide a new and superior built soap.

Another object of the invention is to provide a method of manufacturing a powdered soap which requires less evaporation of moisture, less equipment and less time than do the methods heretofore used.

Commercial fatty acids, as market commodities, are in a relatively dry condition. Alkali reacting salts are obtainable on the open market in relatively dry condition. It is the concept of this invention to form a fluid or agglomerate comprising fatty acids and alkali reacting salts with the components too dry to permit substantial chemical reaction between them when in the fluid state, then to spray this fluid into a reaction chamber while moisture suillcient in quantity to induce rapid chemical reaction is simultaneously added thereto, and controlling the temperature of atmospheric conditions in the reaction chamber whereby the sprayed particles in flight therethrough are rendered hard and non-tacky. One way of carrying out the process is to form a fluid of fatty acids and alkali salts, then atomize the fluid with steam in a reaction chamber. The particles of soap so formed fall to the bottom of the chamber without taking up enough moisture to make them tacky. The excess of steam may be removed from the top of the chamber. I

For instance, 45 to 65% fatty acids in liquid condition may be mixed with 55 to suitable alkali or alkali metal salts, or combinations thereof, and the fluid so constituted atomized with steam at a. pressure of approximately 50 to 60 pounds. The resulting product is a mass of substantially spherical, hard, untacky particles, each one comprising an admixture of saponifled fatty acid and alkali metal salts. This product is suitable for a great variety of detergent purposes. One combination which I have found particularly useful is 50% oleic acid and 50% soda ash. Other suitable alkalies or mixtures of alkalies may be used in place of the soda ash.

When desired, other types of detergents may be included in the fatty acid alkaline salt fluid. For instance, the oil soluble mineral oil sulphonic acids or mahogany sulphonates, or salts of the type recovered as by-products of refining white oil or the light colored technical oils with fuming sulphuric acid or sulphur trioxide, may be added. Other types of sulphonated detergents may likewise be used, for instance. the sulphonated hydrogenated higher alcohols and sulphonated glycerides. These materials may be used in proportions of from 5 to 50% of the weight of the fatty acids employed in the process.

The process will be better understood in relation to the explanation of the operation of one type of equipment which may be used in carrying out the process.

Reference is directed to the accompanying drawing, in which:

Figure 1 represents a diagrammatic longitudinal section of the spraying apparatus and the means for withdrawing the finished product from the production equipment.

Figure 2 is a transverse section of the apparatus taken on the line 2-2 of Figure 1.

Referring particularly to the drawing, a hopper into which the saponification alkali may be introduced is mounted above a brush sifter 2 for gravity discharge from the hopper thereto. The hopper preferably contains a gyratory or rotary element for continuous gradual feed of the material to the brush sifter. The brush sifter 2 may be of a conventional type and is used for the purpose of eliminating lumps and agglomerated particles. The brush sifter is mounted so as to discharge into a mixer 3. The mixer may be of the conventional type and driven at a suitable speed.

Fatty acid is supplied from a storage tank 4 being withdrawn therefrom through a pump 5 and passed to a heater, preferably of the closed type, through the line "I. The heater is preferably heated by steam supplied through the line 8, the condensate thereof being trapped off from the heater through the trap 9. The heater raises the temperature of the fatty acid to a suitable reaction temperature.

To provide uniformity of operation, and uniformity of product, the quantity of fat oil flowing to the mixing apparatus is preferably controlled to a constant rate of flow. One means for providing such control is by the use of a weir box H), which has annexed thereto a discharge outlet l I, and an overflow outlet [2. The overflow outlet extends upwardly in the box to receive overflow of oil or fat when the level in the box is above the predetermined height desired. The discharge outlet contains an orifice plate 13, having an orifice therein, suitable to provide a predetermined rate of flow, under the constant head maintained by the overflow l2. Overflow from the box is directed back to the supply tank 4 or pump 5 through line I4 for recirculation. The pump discharge is adjusted to supply an excess quantity of oil to the weir box 10.

In the overflow discharge line l2 and the main discharge line H from the weir box 10 are provided funnel receptacles 15 for observation of flow. The fatty acid is introduced to the mixer 3 through the line I 6 at a point whereby suitable mechanical mixing of the fatty acid and the alkali in the mixer occurs to provide a pasty or slurrylike mass.

At the discharge end of the mixer 3 is located a gear pump I! of a suitable type whereby the slurry or mixture from the mixing apparatus may be subjected to pressure. The gear pump I! discharges directly to an atomizer l8. Steam is supplied to the atomizer through line I9, pressure being indicated by the gage 20. Condensate is trapped from the steam line at a point just preceding the atomizer through the trap 2l. The atomizer is located at one end of a reaction chamher or room, generally indicated by 22.

The atomizer or nozzle projects fine particles of the material into the reaction chamber and the steam used for atomization purposes supplies the moisture necessary to initiate saponification of the fatty acid-alkali agglomerate, and at the same time provides sufficient temperature within the reaction chamber to assist completion of the reaction and drying of the particles as the particles drop through the heated atmosphere to the reaction chamber floor. The reaction chamber is vented as at 22.

Any type of atomizing nozzle or apparatus satisfactory for atomizing heavy materials of like nature is suitable. If a mechanical or air operated type of atomizer is used, provision may be made for the introduction of an adequate quantity of water thereto. With a steam operated atomizer it is preferable that the amount of steam used be approximately 25% of the weight of the soap forming mixture. The amount of steam which condenses is insufiicient to dissolve the amount of alkali.

To facilitate removal of the soap powder from the reaction chamber, any suitable device or method may be used. The drawing discloses a flat conveyor belt 23 sustained on suitable rollers 24. of the reaction chamber 22 to direct the powdered material to the conveyor belt. To eliminate or reduce dust emanation from the reaction chamber and especially in those areas where the belt emerges from the reaction chamber, a tail piece 28 is mounted at a suitable height above the conveyor belt. In the reaction chamber between the defiector plates 25 is mounted a plate 21 in such manner that a conduit between the tail piece 26 and the belt 23 and the plate 21 is constituted. The nozzle creates negative pressure at the discharge end of the conduit with the result that air is swept inwardly from outside the reaction chamber over the belt and the material located thereon through the conduit. The conveyor belt may discharge into any suitable hopper apparatus in which the prepared product may be stored or directed to dispensing receptacles.

In this manner, a detergent having very desirable qualities may be constituted in a cheap and efficient manner. Other detergent or soap building materials may be added also to the finished product, if desired.

Having described my invention, I desire to be limited only by the ensuing claims:

1. The method of making an alkali soap, said method comprising admixing sodium carbonate and liquefied fatty acids in the absence of any substantial quantity of moisture, then atomizing said admixture by means of steam, the quantity of steam utilized being related to the quantity of sodium carbonate and fatty acids in admixture so that the fatty acids are saponified by the sodium carbonate while in the atomized condition and the particles so formed are hard and not tacky, the quantity of steam being lesser in amount than the amount required to dissolve the sodium carbonate.

2. The method of making soap which comprises suspending substantially dry alkali soap-forming Deflector plates 25 are mounted to the sides materials homogeneously in liquid fatty acid to provide a liquid admixture, and then atomizing said liquid admixture with a quota of moisture suflicient to provide the water necessary to support the reaction between the fatty acid and the alkali but lesser in amount than the quantity required to dissolve the alkali.

3. The method of making a hard, granular soap without the use of appreciable quantities of moisture, comprising, making a slurry of fatty acid and alkali, both of which are substantially moisture free, subjecting said slurry to atomization while moisture sufficient in quantity to initiate rapid saponification but lesser in amount than the quantity of moisture required to dissolve said alkali, is simultaneously added thereto, and then projecting said atomization product into a heated atmosphere conducive to saponification completion, said moisture simultaneously added during atomization being controlled in amount so that the particles fallen through the heated atmosphere remain discrete.

4. The method of making a soap, comprising, associating a liquefied fatty acid and an alkali into a substantially moisture-free mixture, and atomizing said mixture in the presence of a quota of moisture smaller in amount than the quantity required to dissolve said alkali, but sufiicient to induce saponiflcationthereby to produce hard granular non-adhering particles.

5. The method of making soap, which comprises, admixing a liquefied fatty acid and an alkali under conditions inhibitory to saponiflcation, and atomizing said mixture with a quota of steam suflicient to induce saponiflcation but insuificient in amount to dissolve said alkali.

6. The method of making soap, which comprises, admixing a liquefied fatty acid and an alkali under conditions inhibitory to saponification, and atomizing said mixture in the presence of a quota of moisture suflicient to induce rapid saponification but insufficient in amount to dissolve said alkali, in a reaction chamber wherein saponification is completed and the projectile particles are dried to a granular, untacky detergent.

7. The method of making a saponaceous detergent comprising associating a liquefied fatty acid and an alkali into a substantially moisture-free, mixture, and then atomizing said mixture in the presence of a quota of moisture suflicient in amount to induce and support saponification, but insuflicient in amount to dissolve said alkali, thereby to produce hard granular non-adhering particles.

ALEXANDER C. BROWN. 

